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First order/Time Phase-Coherent speakers discussions

"The game is done! I’ve won! I’ve won!"


I would like to use this thread to talk about this subject which I find rather fascinating and somewhat difficult to get my hands on. I went through a course in electromagnetism in college and I have to say this is even more confusing and you won’t find the answer in calculus, physics, Einstein relativity be damned it’s not in there either and definitely not in quantum physics. Listening to the "experts" from Vandersteens and Stereophile but ultimately it all came down to a missing link sort of argument ... something like this:
"Since if a speaker can produce a step response correctly, therefore it is time-phase coherent, and therefore it must be "good".

It’s like saying humans come from chimps since they share 90% genetic content with us, but we can’t find any missing links or evidence. FYI, we share a lot of gene with the corn plants as well. Another argument I’ve heard from John Atkinson that lacks any supporting evidence and he said that if everything else being equal, time-phase coherence tends to produce a more coherent and superior soundstage, but to the best of my knowledge, nobody has been able to produce some semblance of evidence since there is no way to compare apples to apples. Speaker "A" may have better soundstage simply because it’s a BETTER design, and the claim "time-phase coherent" is just a red herring. There’s no way one can say the "goodness" from "time-phase coherence" because you can’t compare apples to apples. Ultimately it’s a subjective quantification.

I’ve been doing some simulation and I will post some of my findings with graphs, plots, actual simulation runs so that we are discussing on subjective personal opinions. Some of my findings actually shows that intentionally making time-phase may result in inferior phase problem and NOT better! (will be discussed more in detail).

Having said all that, I am actually in favor of first order/time-phase coherent if POSSIBLE. I am not in favor of time-phase coherence just for the sake of it. It’s just that there are a lot of mis-information out there that hopefully this will clear those out. Well hopefully ...

Here my preliminary outline:

1. My "subjective" impression of what is "musicality" and how it’s related to first order filters.
2. Interpretation of step-response. I’ve read a lot of online writing with regard to the interpretations but I think a lot of them are wrong. A proper interpretation is presented with graphs and simulations.
3. A simulation of an 1st order and higher order filters with ideal drivers and why time-phase coherence is only possible with 1st order filter. This part will use ideal drivers. The next part will use real world drivers.
4. A simulation with actual drivers and how to design a 1st order/time phase coherent speaker. Discuss pros and cons. And why time-phase coherence may actually have phase issues.
5. Discuss real world examples of time-phase coherence with Thiel’s and Vandersteens speakers (and why I suspect they may not ultimately be time-phase coherent in the strictest sense).
6. I’ll think of something real to say here ... :-)
andy2
atdavid
736 posts
 
Posted without comment:

With just over a month left until its global debut, pre-orders for the Porsche Taycan electric sportscar – which it is understood will be released in three variants – have surged to 30,000.

This is 50% more than Porsche’s original first year target run of 20,000 Taycans, and more than the entire number of reservations for fellow automaker Volkswagen’s electric ID3 hatchback (the latest count from VW sales and marketing boss Jurgen Stackmann in mid-July being 22,000).

The numbers, which no doubt justify the German premium carmaker’s decision to double its first year production run to 40,000 in January, were confirmed by Porsche’s HR director Andreas Haffner at an event in Zuffenhausen, as reported by German news site Handelsblatt on Sunday (Euro time).


Ferrari just launched Its most powerful street-legal car ever — a 986 horsepower road bullet with three electric motors.

The SF90 Stradale marks Ferrari’s first plug-in hybrid that’s not built for the racetrack. It’s powered by a 4.0-liter turbocharged V8 that generates 769 horsepower, but gets another 217 horsepower from three electric motors — one powering the rear wheels and two for the front.


Let's also not forget the P100D is the fastest accelerating production cars till at least 60mph, and the P90 not far off, so essentially supercars. There are a lot of them out there.



andy2 OP688 posts10-30-2019 10:34pm
High end expensive stuff from companies with sufficient depth to design and program signal processing electronics, i.e. like Harman companies, are doing high end in digital.

That’s not I see in REAL life. Most of the most expensive speakers on the market are analog. I can only speak with real life examples. Sure with imagination anything is possible. There are a few digital stuffs but they are few and far in between and hi-end market does not take them seriously. Like Ferrari or Porsche or Lamborghini, nobody wants to drive an electric supercar.

andy2 OP
1,555 posts
 
Real life statistics: what is the percentage of speakers sold here on Audiogon that are digital?  It can't get more real than that.
aschuh's avatar
aschuh
42 posts
 
For what it is worth:
The genetic difference between chimpanzees and man is 1%. Any two random humans differ by less then 0.1% genetically.
 Message: Small differences matter.
In my experience, time/phase coherent  speakers reproduce for example the applause of the audience in a life-like manner. Depending on the recording technique, they reproduce a space better.
Inches matter. The distance between your ears or time difference of the arrival of a sound is what allows to localize the origin of a sound. Say that’s 6 inches or ~ 16 cm. Some may have bigger heads.
1 cm doesn’t matter? Think again.
atdavid
736 posts
 
I think you need to work on your bias as it is unjustified. More and more of the high end speaker market will go digital/active cross-over as the limits of analog cross-overs are a hard brick wall that cannot be scaled. I suggest doing some reading into it, it will likely change your bias if you keep an open mind about it.

If your turntable is only $5K, almost entry by audiophile standards today, then a good DAC, not even one that expensive streaming 24/96 or 24/192 either Qoboz or Tidal is certainly going to touch it if you compare recording to recording. So much has changed in just the last 5 years.

I will emphasize again there is distortion in dynamic speakers that cannot be corrected with an analog cross-over. It just cannot be done. In the digital domain, there is even the ability to address resonances that again, you just cannot do in analog.
I am actually working on a "DIY" 3-way right now, with Accuton mid-bass and midrange. I have not picked my tweeter yet. The level of driver integration and flatness of response after correction is just not possible with an analog cross-over.


andy2 OP689 posts10-30-2019 10:54p
I am not going to use any stinking digital with my high end drivers bought from Seas or ScanSpeak or Accuton. It’s like taking Ms. Kate Upton to McDonalds OK !!!

What am I going to do with my $5K vinyl table? Ain’t no stinking ADC will touch it lols.

Why would I want to use the same design methods we have been using for 100 years when superior ones exist? Lead, follow or get out of the way :-)

andy2 OP690 posts10-30-2019 11:22pmReal life statistics: what is the percentage of speakers sold here on Audiogon that are digital? It can’t get more real than that.

tomic601's avatar
tomic601
13,070 posts
 
nice Little Feat reference Geoff, didn’t know ya had it in ya

” but only time will tell IF he’s a legend from heaven, or sent here from hell” Speaking of time, since 1977 with more than a quarter million time and phase ( and other cool stuff, because you know its a SYSTEM ) loudspeakers sold :-)

my vote is legend... 
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